Field of the Invention
This invention relates to receipt and acceptance verification techniques for documents, license agreements, contracts, or computer programs generally; more specifically, it relates to techniques for verifying receipt and acceptance of electronically transmitted and/or magnetically recorded data objects.
While a variety of prior art techniques exist for protecting electronically transmitted and/or magnetically-recorded data objects, all of these that are presently known require either encryption and the use of a decrypting key or algorithm which is normally only available to a previously authorized recipient, or they require prior approval for sending to the recipient. Other than by these techniques, no present system or technique is known which is self-verifying as to the fact that the recipient has actually received the data object, agreed to the authorization conditions of its receipt or use and installed it for reading or use.
In the field of computer program products, i.e. "software", unauthorized duplication and/or access and usage is a common problem. U.S. Pat. No. 4,757,534 shows one example of a cryptographic technique for protecting such programs. The user must have a password which will allow the encrypted program to be recovered at a prescribed and designated site that has a properly implemented and initialized decryption feature.
Similarly, U.S. Pat. No. 4,757,533 deals with a security system for a personal computer which utilizes automatic encryption and decryption for files in the personal computer.
These prior art systems, and others of similar type, require the prearranged installation of encryption or decryption features and/or "keys" such as passwords before a user or recipient can utilize an electronically-delivered or magnetically-recorded and delivered data object that has been protected by encryption or other disabling techniques. This is a significant drawback in the field of computer programing sales and use, particularly in the over the counter market or in systems which would download application programs for use at a local workstation or personal computer/system. In the latter instance, the program or data object would be electronically transmitted and received, but elaborate systems are used to preauthorize the recipient by giving passwords or the like which must be carefully recorded and kept track of for accounting purposes and for billing.